Cells, tissues, organs and organ systems

A root is a plant organ.

Plant roots contain many different types of tissue.

What is a tissue?

Tissue in the tip of a plant root contains stem cells.

Stem cells can differentiate into any type of cell.

Name the type of tissue in plants that contains stem cells.

In the past many drugs were extracted from plants.

Aspirin is a painkiller.

Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant.

Chemical A can be used as a painkiller.

Table 5 shows information about where chemical A is found.

The scientists usually extract chemical A from the berries of the deadly nightshade plant.

Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves).

The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 5.

Calculate the mass of chemical A in 200 g of the leaves with chlorosis.

Give your answer in mg.

Suggest one reason why the leaves of the deadly nightshade plant have chlorosis.

Chemical A has not been tested in large-scale clinical trials in the UK.

It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public.

Give two reasons why.

There are many online reports making claims about the effects of chemical A.

Some of these reports are biased.

Suggest one reason why a report making claims about the effects of chemical A may be biased.

How can scientists be sure that claims about new drugs are valid?

Tick (✓) one box.

A root is a plant organ. Plant roots contain many different types of tissue.

What is a tissue?

Tissue in the tip of a plant root contains stem cells. Stem cells can differentiate into any type of cell. Name the type of tissue in plants that contains stem cells.

In the past many drugs were extracted from plants.

Aspirin is a painkiller. Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant. Chemical A can be used as a painkiller. Table 1 shows information about where chemical A is found.

The scientists usually extract chemical A from the berries of the deadly nightshade plant. Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves).

The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 1.

Calculate the mass of chemical A in 200 g of the leaves with chlorosis. Give your answer in mg.

Suggest one reason why the leaves of the deadly nightshade plant have chlorosis.

Chemical A has not been tested in large-scale clinical trials in the UK.

It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public. Give two reasons why.

There are many online reports making claims about the effects of chemical A. Some of these reports are biased.

Suggest one reason why a report making claims about the effects of chemical A may be biased.

How can scientists be sure that claims about new drugs are valid? Tick (✓) one box.

A cactus is a plant that lives in a dry environment. Figure 6 shows part of a cactus plant.

Give one adaptation shown in Figure 6 that helps to prevent the cactus from being eaten by animals.

A plant may produce poisons that make animals unwell. What is this type of defence mechanism?

Tick (✓) one box.

Some desert plants only grow leaves after it has rained. As soon as the soil dries out, the leaves fall off. How could the leaves falling off the plant be an advantage to a plant that lives in a dry environment? Tick (✓) one box.

The stem of a cactus is green.

What causes the green colour in the stem?

What is the advantage to the cactus of having a green stem?

The stem of a cactus contains many different tissues.

What name is given to a group of tissues working together? Tick (✓) one box.

Name one substance transported through the xylem in the stem of the cactus.

Name the tissue that transports dissolved sugars through the stem of the cactus.

Figure 11 shows the internal structure of the human heart.

Which organ system is the heart a part of?

Draw a ring around one valve on Figure 11.

What is the function of the valves in the heart?

Valves are also found inside some blood vessels.

Which type of blood vessel contains valves?

Sometimes a valve in the heart can begin to leak.

A leaking heart valve may be replaced with either:

• a mechanical valve

• a biological valve from a pig.

Table 6 shows information about the replacement valves.

Suggest two reasons why a patient may choose a mechanical valve and not a biological valve from a pig.

Suggest one reason why a patient may choose a biological valve from a pig and not a mechanical valve.

A person may develop other medical conditions.

Draw one line from each medical condition to the correct treatment.

Medical condition
Treatment

Plants are made up of cells, tissues and organs.

Draw one line from each level of organisation to the correct plant part.

Level of organisation
Plant part

Figure 3 shows a plant cell drawn to scale.

Where in a plant would the cell in Figure 3 be found?

Tick one box.

Calculate the length of the chloroplast labelled in Figure 3.

Cells in plant roots do not photosynthesise.

Give one reason why.

As a plant grows, new root hair cells are formed from unspecialised cells.

How does an unspecialised cell become a new root hair cell?

Tick one box.

Scientists can clone plants using tissue culture.

Figure 4 shows the process of tissue culture.

Why might scientists want to clone plants?

Tick one box.

What is the advantage of cloning plants using tissue culture?

Tick one box.

The growth medium in Figure 4 helps the plants to grow.

Name one substance in the growth medium.